Your cat has been sleeping more than usual. She stopped jumping onto the windowsill three days ago. Her gums look pale almost white and she hasn't touched her food.

Most cat parents assume it's stress or a stomach upset. Few would guess the answer is a blood parasite that has been quietly destroying red blood cells from the inside.

Hemotropic mycoplasmosis also called feline infectious anaemia is a bacterial infection in which a microscopic organism called Mycoplasma haemofelis attaches to a cat's red blood cells and triggers the immune system to destroy them. The result is haemolytic anaemia, a drop in red blood cells that can develop quickly or slowly and causes weakness, pale gums, fast breathing, and loss of appetite. It is transmitted mainly through fleas and bite wounds, and it can affect both indoor and outdoor cats. Treatment requires antibiotics and, in severe cases, hospitalisation.

Key Takeaways

• Hemotropic mycoplasmosis (feline infectious anaemia) is caused by Mycoplasma haemofelis, a bacterial parasite that lives on red blood cells and triggers their destruction.
• The most visible warning sign is pale or white gums this is a red flag that requires a vet visit the same day, not a wait-and-see.
• Three species of this organism exist in cats; M. haemofelis causes the most severe disease, while the other two often produce mild or no symptoms in healthy cats.
• Fleas are the most strongly suspected route of transmission. Regular flea control is the single most effective prevention step.
• Blood smear tests often miss this infection PCR testing is more reliable and your vet should order it specifically.
• Some cats remain carriers after treatment and can relapse under stress. Recovery requires follow-up bloodwork, not just finishing the antibiotics.
• Indoor cats are not fully protected fleas, mosquitoes, or a new cat in the home can still bring the infection in.

What Is Hemotropic Mycoplasmosis in Cats?

Hemotropic mycoplasmosis is a blood infection in cats caused by a group of specialised bacteria called hemoplasmas bacteria that live directly on the surface of red blood cells. The name tells you exactly what they do: "hemotropic" means blood-seeking, and "mycoplasmosis" refers to the type of bacteria involved Mycoplasmas, which are unusual bacteria because they have no cell wall.

This condition has had several names over the years. Older texts call it feline infectious anaemia (FIA) or hemobartonellosis, and many Indian vets still use these terms. The organism was previously called Hemobartonella felis before genetic sequencing reclassified it within the genus Mycoplasma. All of these names point to the same disease.

According to SpectrumCare, once Mycoplasma haemofelis attaches to the surface of red blood cells, the body may identify those cells as foreign and begin destroying them. This is called immune-mediated haemolytic anaemia the cat's own immune system is responsible for the destruction of red blood cells, triggered by the parasite's presence.

The result is a drop in red blood cells, meaning less oxygen gets delivered to the body's tissues. This is what causes all the visible signs: weakness, pale gums, rapid breathing, and collapse in severe cases.

This is not a worm, a tick, or a typical intestinal parasite. It behaves like none of those. It lives inside the bloodstream and is managed very differently which is why it is commonly missed, misdiagnosed, and undertreated.

Animeal note: If your cat has been diagnosed with unexplained anaemia and your vet has not yet tested for hemotropic mycoplasmosis, ask about PCR testing specifically. This infection is one of the most commonly overlooked causes of feline anaemia in India.

The Three Species: Which One Is Most Dangerous?

Three species of hemoplasmas are known to infect cats worldwide. They are not equally dangerous, and telling them apart matters for treatment and prognosis.

The Merck Veterinary Manual notes that M. haemofelis is the most pathogenic it can cause acute, severe, or even fatal haemolytic anaemia in otherwise healthy, immunocompetent cats. The two Candidatus species are far more common in the general cat population but typically cause problems only when a cat also has FeLV, FIV, or significant immune suppression.

When a cat is infected with more than one species at the same time, or when infection coincides with FeLV or FIV, the disease tends to be more severe. This is why FeLV and FIV testing is a standard part of the diagnostic workup for any cat suspected of having this infection.

What Are the Signs of Hemotropic Mycoplasmosis in Cats?

What does hemotropic mycoplasmosis look like in a cat?

The signs of hemotropic mycoplasmosis reflect anaemia a shortage of red blood cells and reduced oxygen delivery throughout the body. Most cats show a combination of low energy, pale gums, and appetite loss. In acute cases, the decline can be rapid. In chronic or subclinical cases, it builds slowly and looks like general malaise for weeks before anyone realises something serious is happening.

Watch for these signs:

• Pale, white, or grey gums and inner eyelids — this is the most important sign; healthy cat gums should be pink
• Extreme tiredness — sleeping more than usual, not getting up for food, not responding to play
• Loss of appetite — skipping one or two meals, then going off food entirely
• Weight loss — noticeable over days to weeks
• Fever — your cat may feel warm to the touch; cats' normal body temperature is 38–39°C
• Rapid or laboured breathing — the body is trying to compensate for low oxygen in the blood
• Fast heart rate — another compensation mechanism
• Jaundice — a yellow tint to the gums, whites of the eyes, or skin, caused by the breakdown products of destroyed red blood cells
• Enlarged spleen or lymph nodes — your vet may detect this on physical exam
• Hiding, depression, or withdrawal — cats in pain or discomfort typically hide
• Collapse — in severe, acute cases, a cat may simply collapse and be unable to rise

One of the most confusing things about this disease is that early signs can look like almost anything: stress, a stomach upset, a bad day. Your cat seems quieter. She stops jumping up. She eats less. These changes can be easy to dismiss for a few days which is exactly when the anaemia may be getting critically worse.

See your vet the same day if your cat has white or pale gums, rapid breathing, weakness, or collapse. These are signs of severe anaemia and they constitute a veterinary emergency. Do not wait for a morning appointment.

How Does a Cat Get This Infection?

How is hemotropic mycoplasmosis transmitted to cats?

Hemotropic mycoplasmosis spreads through direct blood-to-blood contact — but the exact mechanism is not always obvious. Transmission is strongly suspected to occur through.

Fleas — Fleas feeding on an infected cat pick up the organism and then carry it to the next cat they bite. This is the most clinically important transmission route and explains why flea control is the cornerstone of prevention. In India's warm, humid climate, fleas are a year-round problem not just a monsoon or summer concern.

Bite wounds from fighting — Cats that fight with infected cats can be exposed through saliva and blood from wounds. According to the Merck Veterinary Manual, hemoplasma DNA has been detected in saliva, on the gingiva (gums), and on the claw beds of infected cats supporting the idea that bite wounds are a genuine transmission route.

Blood transfusions — An infected donor cat can transmit the organism to the recipient. This is why blood donor cats should be tested for hemoplasmas before donation.

Mother to kittens (vertical transmission) — Pregnant cats can transmit the infection to kittens. Kittens born to infected mothers may be born infected or infected during feeding.

Other biting insects — Mosquitoes, ticks, and lice have been suggested as possible vectors, though the evidence is less definitive than for fleas.

What does NOT spread it: Shared food bowls and litter trays are not considered significant routes of transmission. Direct contact without blood exposure is generally thought to be low risk.

Which Cats Are at Higher Risk?

Not every cat faces the same level of risk. Understanding who is most vulnerable helps you know when to be especially alert.

Outdoor and free-roaming cats — Significantly higher risk because of flea exposure and fights with other cats.

Intact male cats — Male cats that roam and fight are among the most commonly diagnosed cats. Neutering reduces roaming and fighting behaviour, which indirectly reduces risk.

Cats with FeLV or FIV — These conditions suppress the immune system, making it far more likely that even a mild hemoplasma species will cause serious disease. Cats with FeLV in particular tend to develop more severe anaemia when infected.

Cats in multi-cat households — Higher flea burden and greater possibility of bite wounds between resident cats.

Cats undergoing stress or illness — A cat that was previously a silent carrier can relapse and become clinically ill when stressed, sick with another disease, or immunosuppressed.

Kittens — Young cats with immature immune systems may be more vulnerable to developing clinical disease.

Post-surgical or immunosuppressed cats — Any significant immune challenge can tip a latent carrier into active disease.

How Is Hemotropic Mycoplasmosis Diagnosed?

How do vets test for hemotropic mycoplasmosis in cats?

Diagnosis starts with a physical examination — your vet will assess gum colour, check for spleen or lymph node enlargement, take the temperature, listen to heart rate and breathing, and look for signs of jaundice. These findings tell the vet how severe the anaemia is and how urgently treatment needs to begin.

Complete Blood Count (CBC) — This measures the number and quality of red blood cells, white blood cells, and platelets. In hemotropic mycoplasmosis, the CBC typically shows anaemia (low red cell count) and may show signs that the body is attempting to regenerate red cells (called regenerative anaemia — actually a relatively positive sign, as it means the bone marrow is responding).

Blood Chemistry Panel — Assesses organ function, liver enzymes, kidney values, and bilirubin (elevated in jaundice from red cell destruction).

FeLV and FIV Testing — Standard in any cat presenting with anaemia. These infections change the severity of disease and the long-term outlook significantly.

Blood Smear — A drop of blood is spread on a glass slide and examined under the microscope. In infected cats, the organism can sometimes be seen as tiny, dark specks on the surface of red blood cells. However, this test has important limitations (see section below).

PCR Testing (Polymerase Chain Reaction) — This detects the actual DNA of the hemoplasma organism in the blood. According to SpectrumCare, PCR is the most sensitive confirmatory test and is far more reliable than blood smear examination. It can also identify which specific species is present, which has treatment and prognosis implications.

In an unstable cat with severe anaemia, diagnosis and treatment may begin at the same time. Your vet may start antibiotics and supportive care while awaiting PCR results in a crisis, stabilising the cat takes priority over waiting for every test to return.

Why a Blood Smear Alone Is Not Enough

This is one of the most important things for Indian cat parents to understand: a negative blood smear does not rule out hemotropic mycoplasmosis.

The Merck Veterinary Manual explains why. Hemoplasmas attach and detach from red blood cells cyclically the number of organisms visible on a smear can fluctuate dramatically from hour to hour. They can essentially disappear from the bloodstream for periods. They also fall off red blood cells and die once blood sits in the EDTA collection tube for too long, meaning a delayed smear examination can miss an active infection entirely.

Even when organisms are present, their appearance on the smear is very subtle tiny, basophilic (dark-staining) dots or rings on the red cell surface that can easily be confused with stain artefact or normal cell inclusions.

The practical message: If your vet suspects hemotropic mycoplasmosis based on clinical signs but the blood smear looks normal, push for PCR testing. In India, PCR for hemoplasmas is increasingly available through specialist veterinary diagnostic labs in metros. Your vet can send a blood sample for analysis. The result changes what happens next.

Treatment Options for Hemotropic Mycoplasmosis in Cats

Treatment depends on how sick your cat is at the time of diagnosis. SpectrumCare lays out a clear spectrum of care from outpatient to intensive hospital management.

Antibiotic Therapy

The main treatment is a course of antibiotics that can penetrate inside cells because mycoplasmas live on the surface of or inside red blood cells, regular antibiotics cannot reach them effectively. The two most commonly used options are:

Doxycycline — The most widely used antibiotic for this condition. Given orally once or twice daily for a minimum of 4 weeks, often longer. In cats, doxycycline tablets should be given with food or water and never dry oesophageal stricture (scarring of the food pipe) has been reported if tablets get stuck in the throat. Liquid formulations or following each dose with a syringe of water minimises this risk.

Marbofloxacin or Enrofloxacin — Fluoroquinolone antibiotics used as alternatives, particularly if doxycycline is not tolerated. Note: enrofloxacin in cats requires careful dosing high doses have been linked to retinal toxicity (vision problems) in cats. This is a prescription medication that your vet will manage.

Never adjust antibiotic doses yourself or stop early because your cat "seems better." Partial treatment is one of the biggest reasons cats relapse. The organism may persist at subclinical levels even when your cat looks fine.

Supportive Care

IV Fluids For dehydrated cats or those with moderate to severe anaemia, intravenous fluids support circulation and help deliver what little oxygen is in the remaining red cells to the tissues.

Anti-nausea medication and appetite support Doxycycline can cause nausea in some cats. Your vet may prescribe anti-emetics and appetite stimulants alongside the antibiotic.

Corticosteroids (Prednisolone) in selected cases Because anaemia in this disease is partly immune-mediated (the immune system attacking infected red cells), short-course steroids are sometimes used to suppress the destructive immune response and slow red cell loss. This decision is made carefully, as steroids can also suppress the immune response needed to fight the infection. Your vet will weigh the risks and benefits for your individual cat.

Blood Transfusion

In cats with severe, life-threatening anaemia pale or white gums, collapse, breathing distress a blood transfusion may be the only intervention that keeps the cat alive long enough for antibiotics to work. Transfusion provides an immediate supply of healthy red blood cells to restore oxygen delivery to tissues.

Blood typing or crossmatching is done before transfusion to reduce the risk of transfusion reactions. This procedure is available at specialist veterinary hospitals in major Indian cities.

Hospitalisation and Oxygen Therapy

Cats with critical anaemia, rapid breathing, or collapse may need to be hospitalised and placed in an oxygen cage to support breathing until the anaemia stabilises. This is advanced care but is available at larger veterinary hospitals in Mumbai, Delhi, Bangalore, and other metros.

Can My Cat Fully Recover? What to Expect

The prognosis for hemotropic mycoplasmosis depends heavily on how severe the anaemia is at diagnosis, how quickly treatment begins, and whether the cat has a concurrent disease like FeLV or FIV.

According to SpectrumCare, many cats improve with timely treatment, especially when the anaemia is caught before it becomes critical. Some cats start improving within days of starting antibiotics. Full recovery of red blood cell counts can take several weeks.

However this is critical to understand many cats remain carriers after treatment. The antibiotic may clear clinical disease and make your cat feel well, but the organism can persist at low, undetectable levels. A future stressor another illness, immunosuppression, surgery, FeLV/FIV progression can trigger a relapse.

What this means practically:

• Finish the full antibiotic course — typically 4 weeks minimum, sometimes longer
• Attend follow-up bloodwork appointments — your vet needs to confirm that red blood cell counts are rising and stabilising
• Watch for relapse signs — if pale gums, lethargy, or appetite loss returns months or years later, tell your vet about the previous diagnosis immediately
• Maintain year-round flea control — reinfection is possible, and flea control is the primary prevention strategy
• Manage stress — cats that have been treated should be kept in calm, low-stress environments and any concurrent illness treated promptly

Cats with severe anaemia, delayed treatment, or concurrent FeLV/FIV have a more guarded prognosis. Cats that need a blood transfusion are typically quite ill, but many still recover with intensive care.

How to Prevent Hemotropic Mycoplasmosis in Your Cat

Prevention is more straightforward than treatment. The key pillars are flea control, reducing bite wound exposure, and monitoring for early signs.

Year-Round Flea Control — the Single Most Important Step

Fleas are the most strongly suspected vector. In India, year-round flea prevention is not optional it is essential. The country's warm, humid climate, especially during monsoon and post-monsoon months, creates near-ideal conditions for flea populations to explode.

FRONTLINE PLUS CAT SPOT ON by Boehringer Ingelheim (available on Animeal) contains Fipronil and S-Methoprene. Fipronil kills adult fleas within 24 hours; S-Methoprene is an insect growth regulator that stops eggs and larvae from developing breaking the flea life cycle rather than just killing the adults you can see. It is suitable for cats from 8 weeks of age and weighing at least 1 kg.

Critical safety note for Indian cat parents: NEVER apply dog flea products to cats. Many dog-specific spot-on treatments contain permethrin, which is acutely toxic to cats and can cause tremors, seizures, and death even from small exposures. Always read the label. If in doubt, ask your vet.

Keep Cats Indoors or Limit Unsupervised Roaming

Outdoor access increases flea exposure, insect bites, and the risk of fight wounds from other cats. In apartment complexes across Mumbai, Delhi, and Bangalore, even "semi-outdoor" cats who use a balcony or terrace can encounter fleas carried in on clothing or by visiting animals.

Prevent and Treat Fight Wounds Promptly

If your cat has been in a fight especially with a stray or unknown cat inspect for bite wounds and have them assessed by a vet. Bite wounds are a suspected transmission route, and early antibiotic treatment of bite wound infections reduces multiple health risks.

Test New Cats Before Introduction

If you are bringing a new cat into a multi-cat household, a basic health check including FeLV/FIV testing and PCR hemoplasma testing is a reasonable step, especially if the cat came from a shelter, stray background, or a household of unknown health status.

Support Recovery with Nutrition and Immune Health

A cat recovering from any blood infection or managing long-term immune suppression benefits from nutritional support. BIOPET VITALI CAT PASTE by Bio Petactive (on Animeal) provides a comprehensive mix of vitamins including Vitamins A, D3, B1, B2, B6, B12, Taurine (essential for feline heart and eye function), and amino acids that support overall immune function and recovery. IMMUNOL LIQUID by Himalaya (on Animeal) is a herbal immunomodulator suitable for cats (dose: 1ml twice daily) containing Guduchi, Ashwagandha, and Shatavari herbs with established use in supporting immune function in companion animals. Neither product replaces veterinary treatment, but both are reasonable supportive supplements for cats in recovery or at ongoing risk from immune suppression.

Indian Cat Parent Corner: Why This Matters Here

India's climate is uniquely suited to flea proliferation. Unlike temperate countries where flea season follows warm months, in most of India particularly in Mumbai, Chennai, Kolkata, and coastal cities fleas are active year-round. The monsoon amplifies this dramatically. Warm, humid conditions accelerate the flea life cycle and make outdoor environments, stairwells, and building common areas significant flea reservoirs.

Most Indian cat parents do not put their cats on monthly flea prevention. The assumption is that indoor cats don't need it, or that fleas are a "dog problem." This is incorrect on both counts. Fleas can be carried indoors on clothing, shoes, bags, or through windows. They can arrive on a visiting dog or a new kitten. Once they establish in a home, they are very difficult to fully eradicate.

The second gap: many Indian vets still rely on blood smear diagnosis alone for suspected anaemia. As explained above, blood smears miss a significant proportion of real hemotropic mycoplasmosis cases because the organisms fluctuate in the bloodstream. If your cat has unexplained anaemia, pale gums, or recurrent weakness and the blood smear has come back negative, ask your vet explicitly about PCR testing for hemoplasmas. In major cities, this test is available through specialist veterinary diagnostic laboratories.

The third gap: FeLV status is often unknown in Indian cats. FeLV (Feline Leukemia Virus) dramatically worsens the severity of hemotropic mycoplasmosis. If your cat has not been tested for FeLV and FIV, this is worth discussing at your next vet visit especially if they go outdoors or have contact with unknown cats.

FAQ

My cat's gums look pale is this definitely hemotropic mycoplasmosis?
Pale gums in a cat are a sign of anaemia, but anaemia has many causes. Hemotropic mycoplasmosis is one of them; others include immune-mediated haemolytic anaemia (a different immune condition), blood loss from internal injury, toxin exposure, kidney disease, and cancer. Pale gums are always a same-day vet visit don't try to diagnose the cause at home. Your vet needs a blood test to determine why your cat is anaemic.

Can indoor cats get hemotropic mycoplasmosis?
Yes, though their risk is lower. Indoor cats can still be exposed through fleas carried in on clothing or other pets, through mosquitoes or other biting insects that enter through windows, or through a new cat introduced to the household. If an indoor cat has been a carrier since a previous infection, stress or illness can also trigger relapse.

Will antibiotics cure my cat completely?
Antibiotics usually resolve clinical disease your cat will feel better, eat again, and red blood cell counts will improve. However, many cats remain long-term carriers of the organism at low levels that are too small to detect. This means a full cure in the microbiological sense is not guaranteed. The practical goal of treatment is clinical remission and return to normal blood counts, with monitoring for relapse.

How long does treatment take?
The standard antibiotic course is a minimum of 4 weeks. Some vets extend this to 6 or 8 weeks. Follow-up bloodwork is needed to confirm the anaemia is resolving. Full recovery of normal red blood cell counts typically takes several weeks even after the infection is controlled.

Is hemotropic mycoplasmosis contagious to people or to dogs?
This organism primarily infects cats. It is not considered a significant human health risk through normal household contact with an infected cat. Different Mycoplasma hemoplasma species infect dogs (M. haemocanis), but the feline species (M. haemofelis) is specific to cats. Standard hygiene handwashing after handling a sick cat is always sensible.

My cat has been treated and is better do I still need to bring her back for follow-up?
Yes. Follow-up bloodwork is important even when your cat appears to have recovered. It confirms that red blood cell counts have genuinely normalised, rules out relapse, and helps your vet decide when it is safe to stop treatment. Cats that skip follow-up appointments are at higher risk of missing a relapse before it becomes critical.

Why are fleas such a big concern for an indoor cat in India?
Fleas can enter any home regardless of whether the cat goes outside. They hitch rides on shoes, bags, clothing, and visiting animals. In India's warm humid climate, they remain active year-round there is no cold-season break that controls the population naturally. A single flea from a common stairwell or visiting guest can establish a household infestation within weeks. Monthly preventative treatment is far more effective and far less expensive than treating an established infestation.

References

1. SpectrumCare — Hemotropic Mycoplasmosis in Cats. https://spectrumcare.pet/cats/conditions/hemotropic-mycoplasmosis
2. Merck Veterinary Manual — Hemotropic Mycoplasma Infections in Animals. https://www.merckvetmanual.com/circulatory-system/blood-parasites/hemotropic-mycoplasma-infections-in-animals
3. VCA Animal Hospitals — Feline Hemotropic Mycoplasmosis. https://vcahospitals.com/know-your-pet/feline-hemotrophic-mycoplasmosis
4. PubMed / NCBI — Feline Hemotropic Mycoplasmas (peer-reviewed review). https://pubmed.ncbi.nlm.nih.gov/20230435/
5. Canadian Veterinary Medical Association — Hemotropic Mycoplasmosis (Hemobartonellosis) in Cats. https://www.canadianveterinarians.net/related-resources/hemotropic-mycoplasmosis-hemobartonellosis-in-cats/